B5-Lite hit record temperature of 95 Degrees C / 203 Degrees F


#1

Wow what a day; I have a pair of B5-Lite radios in service for a event inwhich my company is sponsoring the Wifi access for here in Las Vegas… and boy did these radio get hot today!

The spec sheet says Operating Temperature is -40°C to +55°C (-40°F to 131°F) well lets just say that on top of a Las Vegas Hotel with a rubber/tar roof we hit a astonishing 203°F exceeding the spec sheet rating by 72°F which in my opinion is insane!

Now granted these units did continue to function at a higher error rate / lower bandwidth rate but compared to other radio manufacturers like E-Band, Radwin & Siklu radios failed miserably!

My Siklu units operate at higher / hardened temperatures here in desert but by design there entire back is a heat sink to help with heat distribution away from critical chips / components.

Mimosa’s R&D team is going to have to rethink the design of these units and all future units so they don’t get ruled out or passed up for consideration by a whole region of wireless IT Professionals.

I know when I shop around for outdoor IT equipment I always buy the units that by design can operate in higher environment and are hardened! But as far as these units are concerned I just wanted to try them out despite there “low” high temp rating.

After this 4 day event is over I am going to have to reconsider whether these units should be marked as lab / test equipment or if they can be put into production use after exceed the max rating for 4+ consecutive days.

I have attached the 24 hour graph showing the high temperatures.

If anyone has any opinions or suggestion please let me know.

Thank you
Donald DAvanzo
Chief Technology Officer
Point Break Solutions / Black Mesa Cloud
www.pb-sol.com / www.blackmesacloud.com
Office: (702)799-9792
Mobile: (702)743-7324


#2

CPU Temp: Temperature on the device CPU (operating range: -40 °C to +110 °C) - this is B5-lite
Internal Temp: Temperature inside the device casing (operating range: -40 °C to +60 °C). - this is b5, b5c
So no problem for another 15 degrees


#3

Hi Donald,

One of the great features on the Mimosa Cloud is the ability to compare data series - either on the same device, or between different devices.

We compared the PHY rate with temperature on your link and do see some correlation, but there are definitely some other problems with the installation that are skewing the results.

In the image below, you will note that the PHY rate on your link fluctuates from 60 to 80 Mbps (20 MHz channel at MCS 4) on one side, and 14 to 20 Mbps on the other side (20 MHz channel at MCS 1/2).

The SLS Roof side of the link has very low SNR at 7-12 dB, but it also has a very high number of short preamble failures which is usually an indicator of other non-GPS-Synchronized radios within 3m (10’). In general, 100 or fewer short preamble errors are tolerable, but seeing thousands of them over time indicates a serious installation placement problem.

Nikolay already addressed the temperature specifications, but I’d like to add that the B5-Lite has an internal heat sink that draws heat away from the CPU (where temperature is measured) and carries it to the outer case through thermally conductive pads.

Other of Mimosa’s products such as the B5 or B5c have larger metal heat sinks and allow for higher gain. Both attributes may be more effective within your environment and use case.